Every year 2.1 million children around the globe die from pneumonia—more than die from HIV, malaria, and measles combined—making it the number one killer of kids under the age of 5. Why so many deaths? Although pneumonia can be successfully treated with antibiotics, even experts sometimes have a difficult time diagnosing it. In the developing world, the infection is either not diagnosed or diagnosed too late for antibiotics to help. Those diagnosis challenges could disappear thanks to the StethoCloud, a custom built stethoscope and mobile phone app system that analyzes a person’s breathing to determine if they have pneumonia.

The StethoCloud is the creation of four students from the University of Melbourne—Hon Weng Chong, Kim Ramchen, Mahsa Salehi, and Andrew Lin—for Microsoft’s student innovation competition, the Imagine Cup. The project won Microsoft Australia’s national Imagine Cup and placed in the worldwide finals. Two of the team members, Chong and Lin, have a medical school background and have interned in developing nations. After a conversation about pneumonia with his mentor at the university, global health expert Dr. Jim Black, Chong spent two weeks in February developing a prototype. “The first one I was like, ‘why aren’t we getting any sounds?’” says Chong, “and the next one, we were getting all this extra noise so we kept refining it.”

Solving the problems of those early versions resulted in a stethoscope that comes embedded with a tiny mic and has been modified to block out external noise and heat. To use the system, a community health worker—or even an unskilled user—simply plugs the stethoscope into the jack on a mobile phone, places it on the appropriate sections of the body, and boots up the phone’s StethoCloud app, which was designed by the computer science and big data experts on the team: Ramchen and Salehi.

The mic captures the sounds of the person breathing and the app uploads the recording onto cloud servers. Then the app analyzes the breathing patterns, makes a diagnosis according to the standards of the World Health Organization—either the subject has pneumonia or doesn’t—and then presents the user with the appropriate treatment plan.

While a regular digital stethoscope runs over $600, the StethoCloud only costs about $20, which is significantly more affordable in the developing nations that are home to 98 percent of childhood pneumonia deaths. And, although a phone is required for the system to work, about “1.5 million pneumonia deaths occur in developing countries with a high enough mobile usage that we can directly address it without distributing anything else,” says Lin.

The team has research protocols going on with the Royal Children’s Hospital in Melbourne and they’ve sent the prototype to hospitals and health organizations in Ghana, Malaysia, and Mozambique. Lin, who previously interned at the WHO, says that getting the StethoCloud put into use “is a complicated process” since “public health organizations don’t always work on the same timeline.” The team hopes to see some level of adoption within the next year in the countries that need it most, since early and accurate diagnosis for even 10 percent of the cases means 210,000 deaths prevented.

Above all, the students are thrilled to be able use their computer science and medical knowledge for good. “We’re deeply passionate about pneumonia, about saving children,” says Lin. “Honestly, this is the dream of every student. This is what you want to do when you’re little. You want to be that one that makes a difference, and that’s what we’re setting out to do.”